Some Biological Properties of Cephalosporin C and a Derivative

Abstract

Some biological properties of cephalosporin C and of a pyridinium derivative, "cephalosporin CA (pyridine)," were examined. Staphylococci, both penicillinaseproducing and non-penicillinase-producing, and some other bacteria tested, were inhibited by 60 to 125 pg cephalosporin C/ml., and S to 20 pAg cephalosporin CA (pyridine)/ml. The ratio of the activity of the two antibiotics varied for different organisms. Resistance developed slowly on repeated subculture of penicillinaseproducing staphylococci in presence of either antibiotic. The minimum inhibitory concentration of cephalosporin CA (pyridine) upon penicillinase-producing staphylococci increased 4 to 8-fold with a 500-fold increase in inoculum size; with cephalosporin C there was a 2-fold increase. Their activity was not reduced by serum. Both substances were non-toxic. They were excreted quantitatively in the urine when given intravenously or subcutaneously to mice. After oral administration less than 5% of the dose was excreted. Cephalosporin CA (pyridine) was about 8 times more active than cephalosporin C in protecting mice from an experimental streptococcal infection, nine doses of 6.25 mg/kg affording complete protection.

ANTIBACTERIAL ACTIVITY OF SOME DERIVATIVES OF 7‐AMINOCEPHALOSPORANIC ACID AGAINST STAPHYLOCOCCUS AUREUS AND SYNERGISM BETWEEN THESE AND OTHER ANTIBIOTICS

“…Antibacterial activity of single antibiotics in vitro Activity of cephaloram, cephalosporin C and benzylpenicillin against various organisms The activity of cephaloram (7-phenylacetamidocephalosporanic acid) against a variety of bacteria is given in Table 2. Comparable results for cephalosporin C and benzylpenicillin are quoted from Jago & Heatley (1961). Cephaloram had the same order of activity as benzylpenicilHin and about 150-times the activity of cephalosporin C against a number of Gram-positive organisms.…”

“…Some of the biological properties of cephalosporin C and cephalosporin CA (pyridine) were described by Jago & Heatley (1961) and by Crompton, Jago, Crawford, Newton & Abraham (1962). The results are given here of further studies on the antibacterial activity of these and related substances, mainly against penicillinase-producing strains of Staphylococcus aureus.…”